Field of the Invention
The apparatus relates to a device for filtering, retaining and disposal of waste water accumulated on a boat.
Many boats, particularly houseboats, include facilities for storage of waste water resulting from use of toilets, showers, sinks etc. Often, a single tank is used to store waste water from such devices until the tank can be emptied either by pumping or by dumping the waste water into the water surrounding the boat. It is not environmentally acceptable to dump such waste water into the surrounding water as this can create pollution problems particularly in lakes etc. Thus, it has been preferable to store waste water until the boat is moored and the tank can be pumped out.
The storage of waste water in a boat requires a relatively large tank which uses an area of the boat which could otherwise be used for storage of goods, food etc. A large tank, when full, can be relatively heavy which can lead to vessel stability problems if the weight of the tank is not apportioned properly. In addition, the storage of waste water in a tank requires the tank be emptied at frequent intervals to avoid unpleasant overflowing of the tank. Furthermore, in order to empty the tank, provisions must be made on land to accommodate mass disposal of the waste water.
It has been found that waste water on a boat can be categorized into two distinct classes. The first class is Grey water, which refers to water from galley sinks, bathroom sinks, showers, bath tubs etc. or from generally any facility of the boat except the toilet. The second class refers to waste from the toilet otherwise known as sewage. Grey water can be released into the water surrounding the boat without presenting an environmental threat. Sewage cannot be released, it must be stored and emptied from a tank as required. Because grey water volume is usually much larger than sewage volume, discharging of grey water would considerably reduce the problem of waste water storage.
The discharge of grey water into the water surrounding the boat can create unpleasant effects, particularly if the discharge occurs in the near shore area. Aesthetically, discharging any material such as grey water in the vicinity of swimmers, bathers, campers, lakeshore property owners or others, is offensive. Any significant amount of grey water dispersed in a concentrated area could create a health concern, particularly if the area does not have a frequent natural change of water (i.e. current).
Discharging grey water itself does not constitute a threat to the environment, particularly if biodegradable cleaning materials are used in sinks and showers and if a pre-filtering device is utilized to filter out grease and solid particles. Filtered grey water is actually very much like the natural runoff entering the lake system except that grey water volume, by comparison, is smaller. It therefore is practical to discharge grey water into a lake or other body of water provided the discharge takes place in deep water areas and provided a pre-filtering device is used to minimize the discharge of grease and solid particles etc. Thus, there is a need for a device to filter, retain and dispose of grey water accumulated on a boat and to allow discharge of that water only when the depth of the water under the boat exceeds a pre-determined value. Such a device is described in greater detail herein.